Hallisey featured among the approximately 100 elementary and secondary students invited Wednesday to the White House Science Fair in recognition of their accomplishments in science, engineering, technology and math.

The 17-year-old not only presented her research at 1600 Pennsylvania Ave., but she also earned some lofty praise from the commander-in-chief during his speech at the fair.

“She reads about the Ebola epidemic in the news,” Obama said. “She decides ‘I want to make a faster, less expensive test for the disease,’ as opposed to a lot of adults who were just thinking ‘How do I avoid getting Ebola? She decides ‘Well, I’m going to fix this.’

The president then quipped: “How about ‘What were you doing in high school?’ Give Olivia a big round of applause.”

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WATCH: President Obama discusses Greenwich High School junior Olivia Hallisey’s Ebola test (at about the 4-minute mark in the video): White House Twitter

The Ebola test developed by Hallisey uses a four-channel card, in which substances known as reagents react with a patient’s Ebola antigens. A silk film keeps the reagents at room temperature, avoiding the need for refrigeration. The test can be done with a sample like saliva within 30 minutes, at a cost of $25 — an economic option for health-care providers in developing nations in West Africa, where the disease has been epidemic in recent years.

Current Ebola tests requiring refrigeration can take up to 12 hours and cost about $1,000 each.

The new test can detect Ebola when patients still have not shown symptoms, a stage at which the disease is less likely to spread and the chances of recovery are greater.

Hallisey was not available for comment Wednesday, but she discussed her research when she was named a Google Science Fair global finalist last year.

“Nothing exists in isolation,” Hallisey said then. “What affects one country affects everyone. We have to work together to find answers to the enormous challenges that threaten global health, our environment and our world.”

In recent months, Hallisey, has traveled extensively to present and discuss her research. She was invited last September to Google’s headquarters in Mountain View, California, where she was announced as the winner of the technology giant’s contest. In January, she traveled to Manhattan for the interview with Colbert on CBS’ “The Late Show.”

She also earned a spot last year on Time’s “30 Most Influential Teens of 2015” list.

Hallisey is the second Greenwich student in the past three years to present at the fair at the White House Science Fair. Then-senior Anne Merrill was invited in 2014 to showcase her research on a form of charcoal known as biochar.

Wednesday’s gathering marked the sixth White House Science Fair, which was launched by the Obama administration in 2010.

“It’s an awesome opportunity from the vantage point of what they do for these kids,” said Andrew Bramante, Greenwich High’s honors science research teacher. “It puts young scientists in the same perspective as the teams that win the World Series or Super Bowl.”